English: Root branching pattern of Lycopodium clavatum var. nipponicum.
a: isotomous dichotomy of 1st order root at the root tip; b: isotomous dichotomy of 1st order root produces two 2nd order roots; c: successive anisotomous dichotomies of 2nd order root produce each pair of 3rd order root; d: 3rd order roots produce fine roots in the manner of isotomous and anisotomous dichotomy.